For instance, if you want to play a Charizard ex from the Obsidian Flames, you can only add four of those cards in your deck, nothing more, nothing less
Knowing theres at least one player at the table willing to help out other players can be nice in games where you arent doing so well
These cards will have different treatments including retro frames, alternative art, and the heavy metal-style treatment first featured in the Party Hard, Shred Harder drop (see "'Magic: The Gathering' 'Secret Lair: Secretversary' Superdrop")
Rare cards, especially from older editions, are netting thousands of dollars in online auctions right now
Innistrad Remastered, for example, has a fixed list of reprints with known rarity distributions, so you can estimate your odds of hitting a 10+ card with reasonable accuracy